BS EN 3-8:2021 - TC标准是一项关于消防灭火器的标准，主要规定了最大允许压力等于或低于30 bar的消防灭火器的构造要求、压力抗性和机械测试要求，以符合EN 3-7的要求。

该标准要求消防灭火器必须符合EN 3-7的要求，并且在最大允许压力等于或低于30 bar的情况下进行测试。消防灭火器的构造必须符合标准的要求，以确保其能够承受正常使用和运输过程中的压力和机械应力。

此外，该标准还规定了消防灭火器的压力抗性测试和机械测试的要求。压力抗性测试旨在测试消防灭火器在最大允许压力下的耐压能力，以确保其能够在正常使用和运输过程中保持完好。机械测试旨在测试消防灭火器在正常使用和运输过程中的耐用性和稳定性。

总之，BS EN 3-8:2021 - TC标准是一项非常重要的标准，它规定了消防灭火器的构造要求、压力抗性和机械测试要求，以确保其能够在正常使用和运输过程中保持完好。消防灭火器是一种非常重要的消防设备，它可以在火灾发生时提供及时的灭火和救援，因此，消防灭火器的质量和性能非常重要。

相关标准
- BS EN 3-7:2018 - Portable fire extinguishers - Characteristics, performance requirements and test methods
- BS EN 3-9:2021 - Portable fire extinguishers - Requirements for the construction, pressure resistance and mechanical tests for extinguishers with a maximum allowable pressure greater than 30 bar, which comply with the requirements of EN 3-7
- BS EN 3-10:2021 - Portable fire extinguishers - Requirements for the construction, pressure resistance and mechanical tests for extinguishers with a maximum allowable pressure equal to or lower than 30 bar and with a fire rating of not less than 55A 233B, which comply with the requirements of EN 3-7
- BS EN 3-11:2021 - Portable fire extinguishers - Requirements for the construction, pressure resistance and mechanical tests for extinguishers with a maximum allowable pressure equal to or lower than 30 bar and with a fire rating of not less than 21A 113B, which comply with the requirements of EN 3-7
- BS EN 3-12:2021 - Portable fire extinguishers - Requirements for the construction, pressure resistance and mechanical tests for extinguishers with a maximum allowable pressure equal to or lower than 30 bar and with a fire rating of not less than 8A 55B, which comply with the requirements of EN 3-7